Diagnosing stage III ovarian epithelial cancer involves a combination of physical examinations, imaging studies, blood tests, and surgical procedures to confirm the presence and extent of the disease. Understanding these diagnostic methods can help patients prepare for the journey ahead and make informed decisions about their care.

Introduction: Who Should Undergo Diagnostics

Women who experience persistent symptoms such as abdominal bloating, pelvic pain, difficulty eating or feeling full quickly, nausea, or changes in bathroom habits should seek medical evaluation. These symptoms can appear vague and are often mistaken for less serious conditions, which is why many ovarian cancer cases are diagnosed at advanced stages.^[1][5]

Epithelial ovarian cancer rarely causes noticeable symptoms in its early stages. As the disease progresses to stage III, where cancer has spread into the abdominal cavity or to lymph nodes, symptoms become more apparent. This happens because fluid begins to accumulate in the abdomen, causing discomfort and visible changes. Women over 65 who have gone through menopause face higher risk, though the disease can affect younger women as well.^[5]

If you have a family history of ovarian cancer or carry certain genetic mutations such as BRCA1 or BRCA2, regular monitoring and early diagnostic testing become even more important. Women with these risk factors should discuss screening strategies with their healthcare providers, even in the absence of symptoms.^[12]

It’s also advisable to seek diagnostics if you notice unexplained weight changes, vaginal bleeding outside of normal periods, or a strong urge to urinate more frequently than usual. While these symptoms can have many causes, they warrant investigation to rule out serious conditions like ovarian cancer.^[5]

Diagnostic Methods for Identifying Stage III Ovarian Cancer

Physical Examination and Pelvic Exam

The diagnostic process typically begins with a pelvic exam, where a doctor inserts gloved fingers into the vagina while pressing on the abdomen to feel the ovaries and other pelvic organs. This allows the physician to detect any unusual masses, swelling, or abnormalities in size or shape. The doctor also visually examines the external genitalia, vagina, and cervix during this examination.^[24]

While a pelvic exam can identify suspicious findings, it cannot definitively confirm cancer or determine its stage. It serves as an initial step that prompts further testing. Many ovarian cancers, especially those that have already spread, may feel different from normal ovarian tissue, but the exam alone is not sufficient for a complete diagnosis.^[24]

Imaging Tests

Imaging studies play a crucial role in visualizing the extent of the disease. Ultrasound scans, particularly transvaginal ultrasound, use sound waves to create detailed images of the ovaries and surrounding structures. This test helps doctors assess the size, shape, and internal structure of any masses present.^[24]

Computed Tomography (CT) scans of the abdomen and pelvis provide cross-sectional images that reveal whether cancer has spread beyond the ovaries into the abdominal cavity, lymph nodes, or other organs. CT scans are particularly useful for identifying the location and size of tumors in stage III disease, where cancer has extended into the peritoneum (the lining of the abdominal cavity).^[24]

Some patients may also undergo Magnetic Resonance Imaging (MRI) scans, which use magnetic fields and radio waves to produce detailed images of soft tissues. MRI can be especially helpful in distinguishing between different types of tissue and assessing whether cancer has invaded nearby organs.

Blood Tests and Tumor Markers

Blood tests cannot diagnose ovarian cancer on their own, but they provide important clues. The most commonly used blood test measures CA-125, a protein that is often elevated in women with epithelial ovarian cancer. High levels of CA-125 can indicate the presence of cancer, but they can also be elevated due to other conditions such as endometriosis, fibroids, or even menstruation.^[24]

Because CA-125 levels are not specific to cancer, doctors use this test in combination with other diagnostic methods rather than relying on it alone. The test is more useful for monitoring treatment response or detecting cancer recurrence after initial treatment.

Additional blood tests may assess overall organ function, including liver and kidney function, to help doctors understand the patient’s general health and readiness for treatment. These tests also help identify any complications that may arise from advanced disease.^[24]

Surgical Diagnosis and Staging

The most definitive way to diagnose ovarian cancer and determine its exact stage is through surgery. In many cases, doctors cannot be certain of the diagnosis or stage until they perform a surgical procedure to remove tissue samples and examine them under a microscope. This process is called surgical staging.^[1]

During surgery, the surgeon inspects the ovaries, fallopian tubes, uterus, lymph nodes, and abdominal organs to see where cancer has spread. They collect tissue samples from different areas of the pelvis and abdomen, including suspicious-looking lymph nodes. The surgeon also rinses the abdominal cavity with a salt water solution and collects this fluid, known as pelvic washings, to check for cancer cells.^[1]

In stage III ovarian cancer, the surgeon typically finds cancer cells in the peritoneum or in lymph nodes at the back of the abdomen (retroperitoneal lymph nodes). The disease may also appear as visible growths on organs such as the liver or spleen, though it has not yet spread inside these organs. The size and location of these growths help determine the specific substage—3A, 3B, or 3C.^[1]

The tissue samples collected during surgery are sent to a laboratory where a specialist called a pathologist examines them to confirm the presence of cancer cells and identify the type and grade of the cancer. High-grade cancers, which are more aggressive, are commonly found in stage III disease.^[5]

Understanding Stage III Substages

Stage III ovarian cancer is divided into three main groups based on how far the cancer has spread. Stage 3A includes two subgroups: Stage 3A1 indicates cancer in the lymph nodes at the back of the abdomen, with the size of the cancer in the lymph nodes determining whether it is classified as 3A1(i) (smaller than 1 cm) or 3A1(ii) (larger than 1 cm). Stage 3A2 means that microscopic cancer cells are present in the peritoneum, and they may also be found in lymph nodes.^[1]

Stage 3B means that cancer growths visible to the naked eye have formed in the peritoneum, but they are 2 cm or smaller. Cancer may also be present in the lymph nodes at the back of the abdomen. Stage 3C, the most advanced substage of stage III, means that cancer growths in the peritoneum are larger than 2 cm. Cancer may also appear in lymph nodes or on the surface of the spleen or liver.^[1]

Understanding these substages helps doctors plan the most appropriate treatment approach and provides patients with a clearer picture of their disease.

Diagnostics for Clinical Trial Qualification

Clinical trials often have specific eligibility criteria that require particular diagnostic tests to confirm a patient’s suitability for enrollment. These criteria ensure that the trial participants have the specific type and stage of cancer being studied, and that they are healthy enough to tolerate the experimental treatment.^[1]

Histological Confirmation

Most clinical trials require histological confirmation of epithelial ovarian cancer, meaning that tissue samples must be examined under a microscope by a pathologist. The pathologist identifies the specific subtype of epithelial ovarian cancer—such as high-grade serous, endometrioid, clear cell, or mucinous—since different subtypes may respond differently to treatments. High-grade serous carcinoma is the most common subtype in stage III disease.^[5]

Imaging and Staging Requirements

Clinical trials typically require recent imaging studies, such as CT or MRI scans, to document the extent of disease. These scans must be performed within a specified timeframe before enrollment, often within four to six weeks. The imaging helps researchers confirm that the cancer meets the stage requirements for the trial and allows them to measure tumor size and location for tracking treatment response.^[1]

Genetic and Molecular Testing

Some clinical trials focus on patients with specific genetic mutations or molecular characteristics. For example, trials testing new targeted therapies may require testing for BRCA1 or BRCA2 mutations or other genetic changes that make tumors more likely to respond to certain drugs. Blood or tumor tissue samples are analyzed in specialized laboratories to identify these genetic markers.^[24]

Genetic testing not only helps determine eligibility for clinical trials but also provides valuable information about inherited cancer risk that may be relevant to family members. If a patient tests positive for a hereditary genetic mutation, their siblings and children may also be at increased risk and might benefit from genetic counseling and testing.^[12]

Performance Status and Laboratory Tests

Clinical trials assess a patient’s overall health and ability to tolerate treatment using measures called performance status scales. These scales rate how well a person can carry out daily activities. Patients must typically have adequate organ function, which is confirmed through blood tests measuring liver enzymes, kidney function, and blood cell counts.

Baseline CA-125 levels may also be recorded before starting a clinical trial. Changes in CA-125 during treatment can help researchers evaluate whether the experimental therapy is working, though this marker alone does not determine treatment success.